Nigel Blackiston has South Australian Derby ambitions for Manapine and expects a distance rise to suit the three-year-old in the Galilee Series Final.

Manapine steps up to the SA Derby journey of 2500 metres in Saturday's Listed race at Flemington, a trip the horse showed he should relish after doing his best work late over 2000 metres at Pakenham last start.

"He's very similar to that nice horse I had who won the VRC St Leger a few years ago called Right Of Refusal," Blackiston said.

"He measures up to that sort of grade, definitely."

Right Of Refusal was second in the 2011 Galilee Series Final when it was staged at Caulfield before he won the VRC St Leger (2800m) at Flemington.

The horse finished 14th as favourite in the South Australian Derby but was later found to be lame.

Blackiston has mapped out the same program for Manapine and believes the horse is on track for the staying features.

He will be one of 11 runners in Saturday's race for which weights have been raised 4kg after late nomination Magicool and New Zealand Derby fourth placegetter Dee I Cee did not accept.

All runners will now carry 58kg.

"The horse is a work in progress and is a typical immature stayer who is improving all the time," Blackiston said.

"This will definitely give us a nice guide if we're heading the right way (towards the Derby)."

Manapine drew barrier two with Dwayne Dunn to ride and Blackiston took positives out of the gelding's last-start sixth at Pakenham against older horses.

"He jumped from a wide gate, he managed to find the fence but then got stuck behind some slow horses. When he got to the outside he rattled home," he said.

Before that, Manapine finished 10th in the Australian Guineas after breaking his maiden at Ballarat earlier in the campaign.

Melbourne Cup fourth placegetter Signoff is set to make his return in Saturday's Ross Stevenson Trophy (1600m) and will carry 57.5kg after the three-kilogram claim of Dunn's apprentice son Dylan.

The Joe Pride-trained Ball Of Muscle, a stakes-winning half brother to star sprinter Terravista, has been installed a $1.95 favourite for the 3AW Community Raceday Handicap (1000m).